System for monitoring and assisting isolated persons, and device for implementing the system

ABSTRACT

This system for monitoring and assisting isolated persons comprises: a unit ( 15 ) decentralized at the desired location for monitoring and assisting the said persons, equipped with a receiver and intended to transmit an alarm signal, in particular by way of the switched telephone network ( 16 ), to one or more defined locations ( 17 ), in particular a monitoring centre, an emergency centre, neighbours or family; and a portable unit ( 1 ) intended to be carried by the said persons, incorporating an emitter which is intended to emit one or more signals in the direction of the decentralized unit ( 15 ), the said signals being intended to initiate the transmission of the alarm signal from the decentralized unit in the direction of the said defined locations, and additionally incorporating means ( 2, 3, 4 ) for detecting that the person carrying the device has fallen, these means being able to initiate the emission, by the emitter incorporated therein, of the said signals which are intended in turn to initiate the transmission of an alarm by the decentralized unit ( 15 ), these means of detection being of the gravimetric or accelerometric type.

The invention concerns a system for monitoring and assisting isolatedpersons, particularly in a domestic environment, that is to say in theirhome, but also in professional and industrial environments and in thecourse of leisure activities. It also concerns a device for implementingthis system.

As regards the domestic environment, recent demographic studies carriedout among the populations of the industrialized nations show asignificant increase in the number of elderly persons and, consequently,in the number of infirm, poorly or handicapped persons, many of themliving alone.

Moreover, whereas hospitalization of these persons for the slightestaccident was for many years the norm, the current trend—with theobjective of both optimizing the comfort of the patients and of reducinghospital costs—is as far as possible to encourage these persons toremain at home and to provide them either with a home visiting medicalservice or a monitoring service.

The problem posed by these persons remaining at home alone lies in therisks of illness, falls and other medical problems likely to affectthese persons, and in their consequences if the said persons do notreceive any help in good time.

Although periodic visits from friends, nurses and others afford somemeasure of security, and although the presence of the telephone makes itpossible, if need be, to alert the competent authorities, somesituations are without solution, especially in cases where the personhas fainted or fallen, preventing him or her from using the telephoneand, as a result, making it impossible to seek help.

In order to overcome this difficulty, systems of monitoring, assistanceand/or surveillance have been proposed in which the person who is ontheir own permanently carries around a small unit which, when it isactivated by the said person, initiates the emission of a signal in thedirection of a centralized device, which is in turn able to initiate thetriggering of an alarm at a monitoring centre, emergency centre and/orneighbours, and it does this by way of the switched telephone network.Such systems have been described, for example, in EP-A-0 522 660 andU.S. Pat. No. 3 914 692.

The proposed system thus unquestionably represents a step forward.However, it is not able to cover all the situations confronted bypersons who are on their own, especially when these persons fall,causing loss of consciousness, or a state in which they are no longercapable of activating the unit they are carrying.

The same problems arise, especially in the industrial environment, andmore particularly in hostile atmospheres, where the inhalation of toxicsubstances or exposure to potential hazards can lead to the personcollapsing directly or as a result of fainting, and where remaining insuch an atmosphere may prove damaging.

SUMMARY OF THE INVENTION

The object of the invention is to make available a system for monitoringand assisting isolated persons which takes these risks into account.

This system comprises:

a unit decentralized at the location for monitoring and assisting thesaid persons, equipped with a receiver and intended to transmit an alarmsignal, for example by way of the switched telephone network, to one ormore defined locations, in particular a monitoring centre, an emergencycentre, neighbours or family;

and a portable unit intended to be carried by the said persons andincorporating an emitter which is intended to emit one or more signalsin the direction of the decentralized unit, the said signals beingintended to initiate the transmission of the alarm signal from thedecentralized unit.

It is characterized in that the portable unit additionally incorporatesmeans for detecting that the person carrying the device has fallen,these means being able to initiate the emission, by the emitterincorporated therein, of the said signals which are intended in turn toinitiate the transmission of an alarm, these means for detecting a fallconsisting of gravimetric means, such as in particular a mercury balldetector, or consisting of accelerometric means, such as a piezoelectricaccelerometer.

In this way, it is possible to overcome the risk of persons being leftin difficult or even critical situations, recent epidemiological studiesshowing that the number of these persons is relatively high and that theconsequnces in terms of treatment are also critical.

In the context of the use of accelerometric detection means, theportable unit is advantageously equipped with three accelerometers,situated in three different directions, in such a way as to detect fallsin the vertical plane, falls in the lateral plane and backward falls.

According to another characteristic of the invention, the portable unitis also equipped with a member which can be activated by the personcarrying it and which is also intended to initiate, in a known manner,the transmission of an alarm by the decentralized unit. This member inmost cases consists of a press-button, but it can of course consist ofany other type of member performing an equivalent function. This membercan, for example, be incorporated in a chain on which the portable unitis hung and which, when it is pulled off, initiates the transmission ofthe alarm.

According to another characteristic of the invention, the portable unitis equipped with a cutaneous impedance switch. In this way, the systemis in the alert state only when the portable unit is in fact being wornby the user, the skin closing the alert circuit incorporated within thesaid portable unit.

According to another characteristic of the invention, the portable unitincorporates a circuit for recovery and storage of the electrocardiogramof the person in question. For this purpose, the portable unit isprovided with a chain which is placed around the neck of the person inquestion, the said chain being equipped at its end, that is to say atthe end opposite the area of attachment of the portable unit, and thus,when it is in place behind the neck, with contact electrodes which areable to take a first information item within the context of the recoveryof the electrocardiogram. Moreover, the casing constituting the portableunit itself includes an electrode, situated on its rear face, so as tobe situated level with the manubrium of the sternum of the individual,so as to permit, in association with the electrode for the neck, theacquisition of the data necessary for creating an electrocardiogram, thelatter being stored in an integrated memory within the said casing. Inthis way, it is possible, in the event of the person fainting, or in theevent of a fall being detected, to very quickly detect the cause of thefaint or the fall, and, where appropriate, to provide suitable treatmentas soon as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The way in which the invention can be put into practice and theadvantages which derive from it will become clearer from the followingembodiment which is given as a nonlimiting example, with reference tothe attached figures.

FIG. 1 is a diagrammatic representation, in the form of a block diagram,of the portable unit according to the invention.

FIG. 2 is a diagrammatic representation of the functioning of the systemaccording to the invention.

Thus, FIG. 1 shows a block diagram of a preferred embodiment of theportable unit of the invention. This portable unit is intended to beworn by the person, generally an elderly person or someone working in ahostile atmosphere.

DESCRIPTION OF THE INVENTION

This portable unit is traditionally in the form of a casing (1) which isof a small size, for example 40 mm×50 mm, and light weight,incorporating a number of electronic components and, firstly, threeaccelerometers (2), as can be seen in FIG. 2. These accelerometers arecalibrated to detect a fall in three planes, namely the vertical plane,the lateral plane and the antero-posterior plane. These accelerometersare also calibrated to emit a signal relating to a fall, for anymovement undergoing an acceleration of about 2 g for a weight of about50 kilos and a height of about one meter.

It is not the object of the invention to describe such an accelerometerwhich is well known per se. The latter traditionally consists of apiezo-electric crystal whose deformation leads to the creation of anelectrical voltage, subsequently interpreted by an electronic circuit,in particular at a processor (3), then converted into a digital signalby means of an analog/digital converter (4), before being transferred toa logic and control section (5).

These accelerometers can also be of the electronic type with silicon.

The logic and control section typically includes software which, as afunction of the signal transmitted by the accelerometer oraccelerometers (2), is able to initiate the emission of a signal by wayof an alarm transmission section (6) and an antenna (7) in the directionof a decentralized unit (14), typically a demodulator, which is placedin the home of the person in question and within range of the saidportable unit. It will be appreciated that it is possible toparameterize the emission threshold of the alarm signal by acting on thesoftware for processing the signal transmitted by the accelerometers,and, consequently, to give the whole arrangement a certain degree ofreliability by overcoming false alarms.

This decentralized unit is known per se and, after receiving an alarmsignal emitted by the portable unit, it is intended in turn to initiatethe transfer or transmission of an alarm signal, for example by way ofthe switched telephone network (16), to a monitoring service, anemergency service and/or neighbours (17), in order to indicate that theperson in question is at risk.

The accelerometer or accelerometers used, as well as the electronicnetwork for transmission of the signal, are configured in such a way asto reduce to a minimum the risks of interference, in particular suddenmovements, so as to make the detection of an incident or of an actualaccident as reliable as possible.

The portable unit (1) is powered electrically by conventional batteries(not shown). Likewise, the decentralized unit (14) is poweredelectrically via the mains network. A plurality of batteries can beprovided in order to keep the said decentralized unit in an operativestate for several hours in the event of a circuit failure or power cut.

Moreover, the arrangement consisting of the portable unit (1) and of thedecentralized unit (15) is clearly referenced in order to beidentifiable by the emergency or monitoring centre (17) when an alarm istransmitted. For this purpose, a binary code specific to each of thesearrangements is introduced into the memory of the logic and controlsection (5), this code being conveyed by the carrier wave of thetelephone network in case of alarm.

According to one variant of the invention, the portable unit (1) isminiaturized in such a way that it is in the form of a microcircuitcontained in an adhesive, and better known as a patch.

According to another variant, this portable unit is incorporated withina watch.

In all cases, and to ensure that the portable unit is indeed being wornby the user for whom it is intended, it incorporates an electricalcircuit equipped with a cutaneous impedance switch. In other words, theelectrical conduction of the skin is used to close the said electricalcircuit, which then emits a signal, in particular in the direction ofthe central unit, indicating that the portable unit is operational andis being duly worn.

In a variant of the above embodiment, the said electrical circuit isadditionally equipped with a delay time system, typically of a durationof about 30 seconds, so that in the absence of contact with the user'sskin, and consequently in the case of the said circuit being open, noalarm signal is triggered, indicating that the portable unit is nolonger being worn. This is particularly of interest when the portableunit is hung from a neck chain and is no longer in contact with the skinwhen the user leans over.

According to a preferred embodiment of the invention, the portable unit(1) also includes means which are able to permit the recording of anelectrocardiogram of the patient. This recording is made possible, onthe one hand, by combining a neck chain (not shown) with the portablecasing constituting the portable unit, this neck chain incorporating atits upper end one or two detection electrodes, the simple contact ofthese electrodes with the neck allowing a measurement to be taken, and,on the other hand, by placing another measurement electrode on the backof the casing (1). For this purpose, the length of the chain isregulated so that the electrode on the back of the casing comes intocontact with the patient substantially at the area of the manubrium ofthe sternum. In this way, means (11) are defined for acquisition of thedata necessary for establishing an electrocardiogram (ECG) associatedwith a circuit for recovery (10) of the ECG. This circuit for recoveryof the ECG (10) is also placed within the casing constituting theportable unit (1).

This electrocardiogram is permanently stored in a memory (9) associatedwith the logic and control section (5) by overwriting the previouslystored electrocardiogram. The memory time is typically 15 minutes.

The logic and control section (5) is also equipped with a selector whichis able to register the said electrocardiogram in a diagnostics register(8), in other words in a memory, in such a way as to allow thepractitioner to analyse the electrocardiogram and consequently to detectthe origin of the cause of the faint or fall, and, as a result, toprovide the appropriate care more rapidly.

The electrocardiogram is advantageously analysed automatically in realtime within the logic and control section in order to detect majorbradycardia or tachycardia, by parameterizing a threshold which is notbe exceeded, respectively a low-frequency threshold, for example 25beats per minute, or high-frequency threshold, for example 150 beats perminute.

It then becomes possible to generate triggering of an alarm signal inthe event of fainting or loss of consciousness, these being phenomenawhich induce a measurable variation in heart rate.

In addition, according to a development of the invention, the memory ofthe logic and control section (5) is charged with managing the dosage ofone or more medicaments appropriate to the disease from which the wearerof the portable unit is suffering, possibly chronically. The content ofthis memory can be accessed by way of a reader equipped with a suitableconnection, allowing the emergency services, where appropriate, to gainaccess to the information which is essential for the treatment that isto be performed.

According to the invention, the casing also includes a press-button (13)or the like which can be activated by the person wearing the portableunit (1), or by a third party, in order to trigger an alarm whennecessary. This press-button can be replaced or complemented by anelectrical member (not shown), for example incorporated in the closuredevice of the said chain, and closing the electrical circuit permittingthe triggering of the alarm signal, this electrical member beingactivated by pulling off the chain holding the portable unit. In fact,with this possibility, triggering of the alarm signal can be made easierwhen the user is in a difficult situation, sometimes making it tricky toactivate a traditional press-button. In addition, this makes it possibleto eliminate the false alarms which result from inadvertently activatingthe press-button.

Advantageously, and with a view to ensuring the greatest possible safetyof the isolated person, the system of monitoring and/or assistanceaccording to the invention includes means making it possible to informthe said person that the alarm signal has indeed been transmitted to themonitoring centre, emergency centre or to the designated third parties.For this purpose, a signal is transmitted by way of the switchedtelephone network from the said centre or the third party or partiestowards the decentralized unit (15), naturally after having transmittedthe alarm to the service concerned, this signal being visualized, forexample, by illumination of the light-emitting diode (12) on theportable unit (1), by vibration of a small buzzer (not shown), or byemission of a pre-recorded audio message, in such a way that the personin distress can see or hear the confirmation that the alarm signal hasbeen properly triggered.

Moreover, in order to ensure that the system, in particular the portableunit (1)/decentralized unit (15) arrangement, is working correctly,these two units are advantageously equipped with a tester (not shown),which consists, for example, of a press-button that is not directlyaccessible, so as not to risk false manoeuvres, and whose activationgenerates an automatic test of the essential functions of the system,without causing transmission of an alarm. The correct functioning of thesaid arrangement can then be visualized, after triggering of the tester,by the illumination of a light-emitting diode of a colour different thanthat (12) indicating the correct transmission of the alarm signal.

The decentralized unit can of course be mounted on the wheelchair of ahandicapped person. In this configuration, the system according to theinvention fulfills its role perfectly, the interface with the switchednetwork being at present fully mastered, especially by employing thedevelopments used for cellular mobile phones.

In the same connection, it is also possible to use a locating interfaceincorporated within the portable unit and the decentralized unit, forexample to permit identification and positioning by satellite—GPSsystem—by equipping the satellite with a complementary interface unit.This embodiment finds an application in cases where the user is mentallydeficient, and where it is necessary to keep track of the individual.

A complete assembly is thus made available which is able to provide asense of added security not just for persons living on their own,particularly in a domestic environment, but also for their familycircle, since in almost all possible situations, particularly ofdistress, an alarm can be transmitted to the services or partiesconcerned. Moreover, such a system is widely applicable to personsworking in isolation in a hostile atmosphere.

All the benefits of such a system and of the associated portable unitwill thus be readily appreciated.

What is claimed is:
 1. Apparatus for monitoring an individual'scondition and summoning help when a potentially dangerous condition issensed, said apparatus including a decentralized unit containing areceiver, a portable unit capable of being carried by an individual thatcontains an emitter means for transmitting one or more output signals tothe receiver of said decentralized unit, said output signals beingarranged to automatically trigger an alarm signal by said decentralizedunit that is sent by a switched telephone network to one or morereceiving centers, said portable unit further including threepiezoelectric accelerometers adapted to sense falls by an individualcarrying the portable unit in a vertical direction, and in a lateraldirection, and in a backward direction, and in response theretoinitiating a transmission by said emitter means.
 2. The apparatus ofclaim 1 wherein said portable unit further includes manually activatingmeans for initiating an output signal.
 3. The apparatus of claim 2wherein said manually activating means comprises a push button switchthat can be cycled by an individual carrying or wearing said portableunit.
 4. The apparatus of claim 2 that further includes a neck chain forcarrying said portable unit and said activating means is mounted in aclosure device for joining both ends of said chain.
 5. The apparatus ofclaim 1 that further includes adhesive means for affixing the portableunit to the skin of an individual.
 6. The apparatus of claim 1 thatfurther includes an electrical circuit that is closed by a cutaneousimpedance switch that is arranged to close when said portable unit isbeing worn or carried by an individual.
 7. The apparatus of claim 1 thatfurther includes circuit means for detecting and storingelectrocardiogram data from an individual wearing or carrying saidportable unit.
 8. The apparatus of claim 7 that further includes a neckchain that is capable of being worn or carried by an individual forsupporting the portable unit, wherein said portable unit furtherincludes a casing containing contact electrodes on its rear face foracquiring electrocardiogram data from an individual wearing the chainwhen the casing is placed over the individual's manubrium of thesternum, said data being stored by an integrated memory within saidcasing.
 9. The apparatus of claim 8 wherein said portable unit furtherincludes a logic and control section for analyzing the acquiredelectrocardiogram data to detect cardiac dysfunctions, and in responsethereto triggering an alarm signal.
 10. The apparatus of claim 1 whereinthe decentralized unit is mounted upon a wheelchair capable of carryingan individual wearing said portable unit, said decentralized unitcontaining a switched telephone network for a mobile unit.
 11. Theapparatus of claim 1 that further includes means for position finding bya satellite.
 12. The apparatus of claim 1 that further includes meansfor informing the individual wearing or carrying the portable unit thatan alarm signal has been sent by the decentralized unit to one or morereceiving centers.